Lead-free solder alloy

Abstract

The present invention provides a lead-free solder alloy having high reliability and excellent solder bonding properties and suited for the mounting of micronized electronic components at low cost. The lead-free solder alloy according to the present invention has a composition containing 0.5 to 1.5 wt % of Ag, 0.3 to 1.5 wt % of Cu, 0.01 to 0.2 wt % of Ni, 1.0 wt % or less of Ga, and the balance being Sn and unavoidable impurities.

The invention claimed is: 
     
       1. A lead-free solder alloy consisting of:
 1.0 to 1.2 wt % of Ag; 
 0.3 to 1.5 wt % of Cu; 
 0.035 to 0.2 wt % of Ni; 
 0.0015 to 0.005 or 0.05 to 0.1 wt % of Ga; and 
 the balance being Sn and impurities. 
 
     
     
       2. A lead-free solder alloy consisting of:
 1.0 to 1.2 wt % ofAg; 
 0.3 to 1.5 wt % of Cu; 
 0.035 to 0.2 wt % of Ni; 
 0.0015 to 0.005 wt % of Ga; and 
 the balance being Sn and impurities. 
 
     
     
       3. A lead-free solder alloy consisting of:
 1.0 to 1.2 wt % ofAg; 
 0.3 to 1.5 wt % of Cu; 
 0.035 to 0.2 wt % of Ni; 
 0.05 to 0.1 wt % of Ga; and 
 the balance being Sn and impurities.